1. Field of the Invention
The invention relates generally to handheld electronic devices and, more particularly, to a handheld electronic device that has a reduced keyboard and that facilitates the entry of text in a message.
2. Description of the Related Art
Numerous types of handheld electronic devices are known. Examples of such handheld electronic devices include, for instance, personal data assistants (PDAs), handheld computers, two-way pagers, cellular telephones and the like. Many handheld electronic devices also feature a wireless or other communication capability, although other handheld electronic devices are stand-alone devices that are functional without communication with other devices. Such handheld electronic devices are generally intended to be portable, and thus are of a relatively compact configuration in which keys and other structures often perform multiple functions under certain circumstances or may otherwise have multiple aspects or features assigned thereto. With advances in technology, handheld electronic devices are built to have progressively smaller form factors yet have progressively greater numbers of applications and features resident thereon. As a practical matter, the keys of a keypad can only be reduced to a certain small size before the keys become relatively unusable.
In language entry applications, such as in a messaging or e-mail application, a keypad must be capable of generating substantially all of the elements desirable or necessary to form the relevant language. For example, in a language that employs Roman letters, a keypad must be capable of generating substantially all twenty-six of the Roman letters. In order to provide such functionality with relatively few keys, some keypads have included multiple linguistic elements per key, such as providing a plurality of Roman letters on each of at least some of the keys when the keypad is used to generate a language that employs Roman letters.
In order to make use of the multiple linguistic elements on any given key, numerous keystroke interpretation systems have been provided. For instance, a “multi-tap system” allows a user to substantially unambiguously specify a particular linguistic element, for example, on a key by pressing the same key a number of times equal to the position of the desired linguistic element on the key. Another keystroke interpretation system includes key chording in which keys are pressed in various combinations to achieve particular results. Still another keystroke interpretation system might include a disambiguation routine which seeks to interpret the keystrokes in view of stored dictionary data, linguistic rules, stored algorithms, and/or the like.
While such disambiguation systems have been generally effective for their intended purposes, such disambiguation systems are not without limitation. In certain applications, the function of a disambiguation routine can be cumbersome if a user must expend substantial effort in entering language. One such situation in which this may occur is in the context of a word that may not already be in the stored dictionary. Another exemplary situation in which this may occur is when a word is already stored in the dictionary but is considered to have a relatively low frequency, and this may require significant input effort by the user to achieve the desired word. Also, a desired word may not already be stored in the dictionary of the device. It thus would be desirable to provide a handheld electronic device having a reduced keyboard wherein the device might make available to a user words and the like that the user might reasonably be expected to enter. Such words and the like might, for example, be somewhat unconventional.